Rivet feeder



Feb. 6, 1951 P. VAN SITTERT ET AL RIVET FEEDER 4 Sheets-Sheet 1 Filed May 28, 1945 RI ET FEEDER 4 Sheets-Sheet 2 Filed May 28, 1945 r E 5 5 E Y m EM wwfiw m mm w WNM A 0 7 [MJ :W E EM .M fl l- 2 4 G 6 2 R... z F

Feb. 1951 P. VAN SITTERT ET AL 2,540,604 I RIVET FEEDER Filed May 28, 1945 v I 4 Sheets-Sheet s 28 FIG.I2

INVENTORJ 84 PAUL LMA/ JITIt'RT TORNE Y5 Feb. 8, 1511 P. VAN SITTERT ET AL 5 9 RIVET FEEDER Filed May 28, 1945 4 Sheets-Sheet 4 INVENTOR$ 84 PAUL WW slrrmr M/Lnw a. GHRRETT BY JOHN h. Ewan Patented Feb. 6, 1951 RIVET FEEDER Paul Van Sittert, Shaker Heights, Milton J. Garrett, University Heights, and John H. Engeln, Cleveland, Ohio, assignors to The Cleveland Pneumatic Tool Company, Cleveland, Ohio, a

corporation of Ohio Application May 28, 1945, Serial No. 596,375

This invention relates to improvements in rivet feeders, more particularly means for assembling a column of rivets in a flexible tubular dispenser from which the rivets may be discharged one at a time into holes previously prepared in the work, and renewing the supply of rivets from time to time as circumstances require.

One of the objects of the invention is the provision of means of the character stated which shall function automatically to maintain the feeder loaded and ready for action.

Another object'is the provision of means for taking rivets from a hopper and arranging them in a column with their stems or shanks all extending in a forward direction toward the delivery end of the apparatus.

Another object is the provision of means for maintaining fluid pressure behind a column of rivets for feeding them forcibly oneat a time into thework.

Still another object is the provision of valve means for intermittently damniing up the flow of rivets from the hopper until a quantity are collected, and thereafter letting them down as a column into a delivery tube, the valve means also functioning to control the flow of pressure fluid partly for operating the valve and partly for applying pressure behind the rivets in the delivery tube.

Other objects and features of novelty will appear as we proceed with the description of those embodiments of the invention which, for the purposes of the present application, we have illustrated in the accompanying drawings, in which Fig. 1 is an elevational view of the complete apparatus embodying the invention.

Fig. 2 is a fragmental elevational view on an enlarged scale illustrating the hopper and associated mechanism.

Fig. 3 is a cross-sectional detail view of the distributor mechanism showing the distributor blade at one extreme of its movement.

Fig. 4 is a similar View showing the distributor blade at the opposite extreme of its movement.

Fig. 5 is a further similar view showing the distributor blade temporarily locked against further movement by the head of arivet. Fig. 6 is a fragmentary sectional view taken substantially on the line 6-6 of Fig. 3.

Fig. '7 is a similar view taken substantially on the line l-! of Fig. 4.

Fig. 8 is a vertical sectional view on a larger 1 Claim. (01. -162) Fig. 9 is a similar view showing the valve closed.

Fig. 10 is a view similar to Fig. 8 of a modified form of valve mechanism, showing the valve open.

Fig. 11 is a view similar to Fig. 10 but with the valve closed, and

Fig. 12' is a detail sectional view on the line |2l2 of Fig. 8.

In the drawings we have shown at l5 a machine casing in which may be mounted an electric motor, an air compressor and other necessary appa-' ratus not directly connected with the present invention. On the top of the casing there is supported a hopper l6 into which a considerable quantity of rivets may be dumped. The rivets may be of the type commonly used in airplane construction, having cylindrical stems or shanks and circular heads; Leading downwardly from the bottom of the hopper there is an inclined guide block ll having a vertical slot l8 therein slightly widernthan the diameter of the rivet shanks l9. These shanks find their way into slot [8, while the circular heads 20 of the rivets rest against the upper surface of the guide block. Rivets that collect on the top of the guide but do. not have their shanks extending into the slot are pushed back by a ribbed rubber wheel 2! A fiat plate 22 is secured by screws 23 to the guide block somewhat to one side of the slot l8, being spaced from the uppersurface of the block along said slot a distance a trifle greater than the thickness of the rivet heads. The rivets are thus held in the position illustrated in Fig. 6 as they slide down toward a distributor block 24. The latter has therein an inclined transverse slot 25 in communication with slot i8 and at right angles thereto. This slot 25 extends entirely across distributor block 24 and has. a distributor blade 26 slidable therein. .Cylindrical hole 2i in block 2 5 is bisected by slot 25 and is disposed to one side of slot [8. Thishole 21 is of a diameter large enough to clear the heads 20 of the rivets, so that the latter may slide down freely therethrough. The lower end of the inclined hole 27 connects with a vertical extension 21, from which a tubular chute 28 of the same bore as holes Zl and 27 leads downwardly. Block 24 in front and behind slot 25 has short upwardly extending projections 29 which constitute stops for a purpose presently to scale of a valve mechanism controlling the flow be described.

Distributor blade 25 is provided with an inverted L-shaped slot having a relatively narrow horizontal portion 3!] and a relatively wide vertical portion 3I. Portion 3B is wide enough to accommodate the thickness of the rivet heads 20,

while the vertical portion Si is wide enough to accommodate the diameter of the rivet heads. In the position of the distributor blade illustrated in Figs. 4 and 5 the vertical portion 3! of this slot registers with the cylindrical hole El. When the blade 26 is in the position of Fig. 3 the bottom rivet in the guide block ll moves down until its shank is received by slot 25, while its head is supported on the top of block 25, as shown in Figs. 3 and 6.

32 is an inclined lever which is pivoted to swing about the shank of a screw 33. At its upper end this lever carries a cam follower 3 1, running upon a face cam 35. The lower end of lever 32 bears against a notched out face 36 of distributor blade 25, and there is attached to this lever one end or" a tension spring 37, the opposite end of which is fastened at 38 to distributor block 24. Spring 3? therefore holds follower 3t against its cam 35 and swings lever 52 counterclockwise when the follower moves down the incline 353 of the cam. Cam 55 is mounted on a shaft 40 which also carries wheel 2] and is rotated at a slow rate of speed by means of a belt 5!. A wire arm 52 extends laterally from lever 32 and at its outer extremity is bent into a loop 33 for the reception of one end of another tension spring lit, the opposite end of which is fastened to the distributor blade at 45. A pin 55 is mounted in distributor blade 26 and is adapted to engage one side of distributor block 2 3 to stop the movement of the blade toward the right, as viewed in Figs. 4 and 5. When the cam 35 causes the lever 32 to swing clockwise, arm 62 causes spring M to pull blade 26 toward the left to the position of Fig. 3, motion in this direction being limited by the engagement of the notched face 36 with the lower fend of lever 32. Spring 31 is somewhat stronger than spring 44.

Referring now particularly to Figs. 8 and .9, .50 is a valve chest into the upper part of which tubular chute 28 extends, the latter being concentric with a bore 5!. A second bore 52 in the lower part of the valve chest is aligned with bore 5i, and a delivery tube 53 socketed in a counterbore of the chest leads downwardly there-- from. The valve chest is provided with a cylindrical valve chamber 5G in which a valve piece 55 is mounted to slide. This valve piece has a bore 56 therethrough of the same diameter as bores 5| and 52 and adapted to be brought into alignment with the latter as shown in Fig. 8. A coil spring 5'! bearing at one end against the! valve piece and at the other against a threaded bushing 58. tends to hold the valve piece in the position of Fig. 8, where a conoidal surface of the valve piece engages a narrow seat 59 surrounding an end chamber 65 in the valve chest. The valve piece may be prevented from turning by means of a screw 55 having a dog point 62 o erating in a longitudinal groove 63 of the valve piece.

The inner end of the valve chamber and the inner end of the valve piece are of a reduced diameter, and where the larger and smaller .portions of the valve chamber meet there is an annular chamber 55 surrounding the valve piece. This annular chamber is in communication with bore 52 by way of a passage 55 in the valve chest. An annular shoulder as formed at the juncture of the large and small diameter portions of the valve piece, is exposed to whatever pressure exists in the annular chamber 54.

An annular groove 6? formed in the small diameter portion of the valve chamber communicates through a short passage 68 with a passage 69 surrounding a needle valve 10 which may be adjusted by means of a threaded portion H and held in adjustment by a lock nut 12. The metered discharge from passage 69 flows through passages l3 and F4 to atmosphere.

i5 is an inlet passage for compressed air which may be supplied from a compressed air line or from a compressor situated within the casing I5. A short passage 16 extends from inlet 15 to valve chamber 54. In the valve piece 55 there is a passage ll, shown herein as of inverted V-shape. In the valve position of Fig. 8 this passage l'lconnects the inlet with an angular passage 18 leading to a somewhat larger passage 19 which receives a needle valve that is adjustable by means of a threaded portion 81 and is adapted to be locked in adjusted position by a.

nut 82. The metered air passing needle valve 80 is free to enter a bore 83 with which a tube 84 connects and to flow through passages 85 and 86 into the end chamber 65. In the valve position of Fig. 9 on the other hand passage 11 connects the air inlet l5 with the space at the top of delivery tube 53 and behind any rivets in that tube or a tubular connection 81 which extends into the casing l5 and upward therethrough to a coupling fia from which a flexible hose'89 extends for conducting the rivets to the desired point of use. Hose .89 may be of ,much greater length than'is illustrated in Fig. land has a rivet chuck so at its extremity which, under the control of the operator, is adapted .to release the rivets one at a time. Tube 84 extends downwardly through the casing into a storage reservoir 9| into which a considerable volume of pressurefiuid must be icy-passed before sufficient pressure can .be built up in chamber 50 to unseat valve piece 55 a ainst the action of spring 51. For the purpose of facilitating manual operation of the valve piece 55, a ring post .92 may be threadably mountedin the outerend of the valve piece.

After a column of rivets has .beenfed from chute 28 through bore 55 inthe valve to delivery tube 53, it is desirable that further rivets be prevented from descending, as they might become wedged between the valve and the valvechest. Accordingly we provide a finger .95 on a loop 96 which surrounds chute 28 near its upper end, this finger being adapted to move through an opening 9'! in the chuteinto the position illustrated in Fig. 8 whereit extends into the path of the next rivet head and dams up any further flow of rivets. This loop 96 is formed integral with a wire 98, the lower end of which is secured in a lever 99 of somewhat unusual shape pivoted at IEO in a slot IM formed in valve chest 55. A spring lllZ tends to hold the lever in the position of Fig. 8. The lower end of lever 99 comprises a lateral projection H33 which extends into the space enclosed by coil spring 51. When valve piece 55 moves to the left, as indicated in Fig. 9, lever 99 swings to the position there illustrated and causes finger 'to' be withdrawn from chute 28, whereupon any rivets then above thefinger are permitted to drop until the lowermost one strikes valve piece 55, as also indicated in Fig. 9.

In Figs. 10 and 11 we have illustrated a modification of the valve mechanism in which pressurefiuid in an endchamber I it is effective at all times against the major part of the endsurface of the valve piece H l. .Howevenin-the "Fig. 10 position the compression spring 51 .isaidedinopposing movement of the valve piece toward the left by one or" more spring pressed ball detents H2 adapted to engage notches H3 in the valve piece. The forces of the springsjl M of these detents are adjustable by means of the backing screws H5. When pressure builds up in chamber H0 sufiiciently to overcome the action of these detents the valve piece will snap over to its Fig. 11 position. In other respects the construction of Figs. and 11 is like that of Figs. 8 and 9,

and a further description of the same is unnecessary.

Operation.Assuming that the valve 55 is in the position of Fig. 9,. andthat a quantity of rivets are present in the hose 89, the delivery tube being connected with the compressed air supply so that pressure is exerted upon the rear end of.

the'column of rivets in the hose, this pressure will be maintained without any material loss inasmuch as the delivery tube is connected with the pressure fluid inlet and inasmuch as any leakage of air must take place around a considerable number of rivets whose heads fit quite closely the inner walls of the hose. The chuck so on the free end or" the hose is a specially designed chuck having trigger release means for permitting one rivet at a time to be discharged shank foremost. The operator holds the chuck against the work opposite a rivet hole and causes the partly protruding rivet to enter the rivet hole. After this rivet is thus placed in its hole the chuck automatically engages the head of the next rivet and prevents further discharge of rivets until the operator is ready to operate the release means for depositing that rivet in another hole. Fo a complete disclosure of a chuck suitable for this purpose reference may be had to an application of John H. Engeln, Eugene W. Lehman and Lloyd G. Speth, filed of even date herewith, Serial No. 596,376.

When the supply of rivets in the hose approaches exhaustion, for example when there remain in the hose somewhere in the neighborhood 'of one-half dozen rivets, the compressed ai behind the rivets leaks past them at a rate such that the pressure in the delivery tube is material- 1y reduced. Then, through the passage 65 in the valve piece, the pressure in annular chamber 64 is likewise reduced and the spring 51 starts to expand. As soon as the V passage Tl passes out of communication with passage 16 there is no force whatever to oppose the action of spring 51 and the valve piece then snaps over to the position of Fig. 8. Thereupon all of the rivets that have collected in the chute 28 quickly descend through the bore 55 into the delivery tube 53, while any rivets above finger 95 are cut oif.

With each revolution of hopper shaft 40 an additional rivet is moved by blade 26 from a position at the base'of guide I! to a position above cylindrical hole 2'! and its extension 21, enabling the rivet to drop through the hole until it strikes the rivet next below. The movement of blade 25 toward the right when the follower 34 moves rapidly to the low spot of cam 35 is rapid because of the strong spring 3! and the left side of the slot 3| in the blade 26, which is in engagement with the shank of the rivet urges the latter toward the right. This movement of the blade is brought to an abrupt stop by the pin :36, but the inertia of the rivet keeps it moving rapidly until its head strikes the projections 29, whereby it is guided into the cylindrical hole 21 with which the wide vertical part 3| of the L-shaped slot is then in register. At this time only a small number of rivets are fed to the-chute above the finger 95, because as soon as a rivet falls into the position marked a in Fig. 5 the blade 26 is locked against further movement. Jamming of the hopper mechanism i thereby prevented.

With the valve 55 in the Fig. 8 position, live pressure fluid will flow from the inlet 15 through the V passage 11 and angular passage 18, through the needle controlled passage 19 and through passages 83 and 84 to reservoir 9 I, Fig. l, and through passages 85 and 86 to end chamber 60. Because of the volume of these passages combined with that of reservoir 55, and because of the metered flow, pressure will build up in chamber 60 somewhat slowly. When it increases sufficiently however, it shifts valve piece 55 to the left away from its seat 59 whereupon a considerably enlarged surface is exposed to the accumulated pressure and the valve piece accordingly snaps over from the position of Fig. 8 to that of Fig. 9. By this valve movement finger is withdrawn from chute 28, the rivets above the finger descend until stopped by the surface of valve piece 55, and the hopper mechanism resumes operation which may'continue until the column of rivets in the chute rises to the position a of Fig. 5, whereupon its operation is again interrupted.

With the parts in the Fig. 9 position, the pressure fluid at the right hand end of the valve chamber and in the reservoir 9! is gradually dissipated through the annular groove 61 and passages 68, 69, 73 and M. In the meantime however, inlet 15 is connected through passages 16 and H with the interior of the delivery tube, which enables pressure fluid to force the column of rivets in the tube down and into the hose 89 until stopped by the few rivets remaining therein. The pressure then quickly builds up and pressure fluid flows through passage 65 into annular passage 64, where it becomes effective against annular shoulder 66 and serves to hold the valve in the Fig. 9 position. The rivets in the hose prevent appreciable leakage of pressure fluid through the chuck at the end of the hose. When their number is sufficiently reduced and leakage occurs the spring 51 again acts, the parts resume their positions of Fig. 8, and the cycle repeats.

The operation of the machine when the valve mechanism of Figs. 10 and 11 is employed is substantially the same as when the mechanism of Figs. 8 and 9 is used. However the snap action of the valve resulting from the sudden increase of surface exposed to pressure fiuid'is not present in this form of the invention. The snap action is obtained in this case by the resistance to movement afforded by the ball checks H2. This resistance continues until the notches H3 cam the balls outwardly far enough to enable them to ride on the surface of the valve piece, whereupon the compressed air at the right hand end of the valve snaps the valve piece over from the Fig. 10 position to that of Fig. 11.

Having thus described our invention, we claim:

In a feed mechanism for rivets or the like, a valve chest, a tubular chute for rivets leading to said valve chest, a delivery tube having an internal diameter slightly greater than the diameter of the rivet heads leading from said chest in alignment with said chute, a valve piece in said chest, a spring at one end of said chest tending to move said valve piece into a first position for connecting said chute and delivery tube, said valve chest having a chamber at its opposite end exposed to the adjacent end of said valve piece and an annular chamber exposed to an annular? surface-.- of: the valve; piece, a st r e reservoir incommunication with said end chamber, meansiefiective when said valvepiece is in said first position for building up pressure in said end chamber and said reservoir for moving'said valve piece, toa second position disconnecting thechute: and; delivery tube, means efiective in said second; position for slowly dissipating the pressure. in said end chamber and reservoir, and means. effective in said second position for introducing. and maintaining pressure fluid in said delivery tube behind the column of rivets therein, said valve, chesthaving therein a passage connecting said delivery tube and said annular chamber, whereby pressure fluid is admitted to the annular surface of the valve piece to maintain it iniits second position as long as the supply of rivets in said delivery tube prevents appreciable leakage therefrom, which leakage will cause escape of the pressure fluid from said annular surface, and thev consequential shifting of the valve-in its first position.

PAUL VAN SITTERT.

MILTON J. GARRETT.

JOHN H- ENGELN.

REFERENCES. CITED:

The following references are of record in they file of this patent:

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